The following description relates to one or more light source apparatuses for an endoscope which apparatuses are adapted to appropriately change light sources for supplying light to the endoscope.
As a system employed when a doctor observes the inside of a body cavity of a patient, generally known is a system to observe, on a monitor, an image of the inside of the body cavity captured through an electronic scope, or a system to directly observe the inside of the body cavity through a fiber scope. Such an observation system has a light source apparatus configured to introduce light into a Light Carrying Bundle (LCB) of the electronic scope or the fiber scope and to illuminate, through the LCB, the inside of the body cavity where natural light cannot be introduced. The light source apparatus is loaded with a high-intensity lamp, as a light source, such as a xenon lamp, a halogen lamp, a mercury lamp, and a metal halide lamp.
In the meantime, the light source of the light source apparatus may be turned off due to the end of life or malfunction of the light source while an inspection or an operation is being implemented for the inside of the body cavity with the electronic scope or the fiber scope inserted into the body cavity. In this situation, the doctor cannot visually recognize the inside of the body cavity. Thus, it results in not only a problem that the inspection or the operation cannot be continued but as well a problem that it becomes harder to pull the electronic scope or the fiber scope out of the body cavity.
As a solution for the aforementioned problems, there has been proposed a light source apparatus which includes a plurality of light sources. In the case where such a light source apparatus is used, even though a currently-used one of the light sources is turned off due to the end of life or the malfunction during the inspection or the operation, it is possible to continuously illuminate the inside of the body cavity by quickly changing the currently-used light source to another one. For instance, Japanese Patent Provisional Publication No. HE19-10174 (hereinafter, simply referred to as '174 Publication) exemplifies a light source apparatus provided with a plurality of light sources.
The light source apparatus of '174 Publication is loaded with two light sources, and provided with a turning table rotatably supported. The turning table has an outer circumferential gear formed on an outer circumference thereof, which gear is configured to engage with a gear attached to a shaft of a stepping motor. The stepping motor is configured to rotate the turning table through the aforementioned gears that engage with each other. Further, the stepping motor is controlled to stop one of the light sources in such a position on an optical axis of the LCB as to get light introduced into the LCB at the highest efficiency. Then, the light source (more exactly, the turning table) is held in the stop position by a holding force of the stepping motor.